Can You Take Expired Aspirin?
In our latest question and answer, the pharmacist discusses the safety of using expired aspirin.
I have a bottle of expired aspirin. I heard that you can tell whether or not it's bad. I am wondering if I can still take this. Can you advise?
Nov 15, 2022- Expired aspirin typically becomes less effective over time and may develop a vinegary smell as it breaks down, though it is unlikely to cause harm. Since aspirin is inexpensive and widely available, it's recommended to simply replace expired aspirin rather than use it. Proper storage in cool, dry conditions away from light and humidity helps medications maintain their potency longer.
Answer
In general, it is not recommended to take medications that have passed their expiration date, including aspirin, as there is the potential that they are not as effective as they once were. This would be especially important for certain medications such as birth control pills and thyroid medication, where a small change in potency can make a significant therapeutic difference.
Aspirin, over time, does break down (and has a distinct odor when it does) and will be less effective.
As aspirin is widely available and relatively inexpensive, it is recommended that you simply replace it if it is expired.
Expired Medication
The problem with expired drugs is you just don't know if they have lost potency. Many don't have any noticeable signs of degradation.
Most drugs don't actually go "bad" in terms of being harmful, but they may have lost potency and thus will not have the desired effect.
Manufacturers typically use 2 to 3-year expiration dates because it is convenient and they eliminate the need to perform long stability tests. Past a few years, there is just a lack of data available to make a good determination of whether or not a drug still retains its labeled potency.
Expired Aspirin
In regard to aspirin specifically, you may notice that it has a slight 'vinegary' smell to it. This can happen with expired aspirin as it chemically degrades over time and what you're smelling is acetic acid.
As unpleasant as it may smell, most studies report that the drug likely holds over 95% of its original potency if it's within a few years of expiration and would typically not be unsafe to take (but may not work as well).
When Do Medications Expire?
While it can be difficult to determine the potency of specific medications after they are expired, studies have shown that most drugs do in fact take a long time to degrade, many times, well past their listed expiration date.
The US military conducted a study in the 1980s on the potency of expired drugs, hoping to avoid the potential of replenishing over $100 million in soon-to-be-expiring drugs. They found the vast majority of drugs were acceptable to use well past the labeled expiration date. This led to the 'Shelf Life Extension Program', a program that allows the stockpiling of potentially important medications past their expiration date.
As mentioned, it is fairly uncommon that expired medications "go bad" and could cause harm. One rare exception is degraded tetracycline. There have been rare reports of kidney damage in patients who took outdated tetracycline in the 1960s.
Medication Storage
It is important to remember that the expected life span of a drug is highly dependent on proper storage.
Exposure to light, air, humidity, and high/low temperatures can greatly affect the degradation rate of a drug. Since there are often too many unknowns, you typically will not hear a healthcare professional recommend that it is OK to take expired drugs like aspirin.
Final Words
Since aspirin is over-the-counter and relatively inexpensive, it generally makes more sense to just purchase a replacement product.
Thanks for reaching out and I hope we provided the information you were looking for!
References & sources
Glossary — Terms in This Answer
- Potency
- The strength or effectiveness of a medication to produce its intended effect.
- Degradation
- The process by which a medication breaks down chemically over time and loses its effectiveness.
- Acetic acid
- A chemical compound produced when aspirin degrades, which creates a vinegar-like smell.
- Expiration date
- The date after which a manufacturer guarantees the medication will maintain its labeled potency.
- Stability tests
- Scientific studies performed by manufacturers to determine how long a medication remains effective under various storage conditions.
- Tetracycline
- An antibiotic medication that can become toxic and cause kidney damage if taken after it has expired.
- Shelf Life Extension Program
- A U.S. military program that allows medications to be stored and used past their original expiration date if testing shows they remain safe and effective.
- Degradation rate
- The speed at which a medication loses its effectiveness, which is affected by storage conditions like temperature and humidity.
Dr. Brian Staiger, PharmD
Doctor of Pharmacy, board certified clinical pharmacist (BCPS), American Herbalist Guild, Medication Therapy Management certified
Brian Staiger, PharmD, BCPS, is a licensed pharmacist with more than 13 years of experience across retail pharmacy, clinical pharmacy, medication safety, pharmacy program development, and healthcare administration. He is the founder of HelloPharmacist.com, where he helps patients...
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